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Pregnancy induces numerous modifications in the musculoskeletal system of the female body. Since one of the essential roles of the lumbopelvic structure is to support mechanical loads in the upright position, this study was designed to simulate the response of this complex to the growing foetus in pregnant women. The authors hypothesized that posture (i.e., lordosis and muscle involvement) under pregnancy conditions might be adjusted to minimize the demands of the obstetrical load. The analysis of the load on the musculoskeletal system during gestation was made based on numerical simulations carried out in the AnyBody Modeling System. The pregnancy-related adjustments such as increased pelvic anteversion and increased lumbar lordosis enhance the reduction of muscle activation (e.g., erector spinae, transversus abdominis or iliopsoas), muscle fatigue and spinal load (reaction force). The results may help develop antenatal exercise programs targeting core strength and pelvic stability. [ABSTRACT FROM AUTHOR]

Featured Application: A platform continuously translating in the horizontal plane in an asymmetric mode can be employed as a means for normalizing the position of the centre of feet pressure in patients standing on it. Various diseases are associated with the impaired control of the medio-lateral (ML) position of the centre of feet pressure (CoP), and several manoeuvres have been proposed for enhancing the CoP symmetry. Here, we assessed in healthy standing subjects the feasibility and outcome of a novel protocol entailing a reaction to a continuous asymmetric ML displacement (10 cm) of the support base. The periodic perturbation consisted of a fast half-cycle (0.5 Hz) followed by a slow half-cycle (0.18 Hz). One hundred successive horizontal translation cycles were delivered in sequence. Eyes were open or closed. CoP was recorded before, after, and during the stimulation by a dynamometric platform fixed onto the translating platform. We found that the post-stimulation CoP was displaced towards the direction of the fast half-cycles. The displacement lasted several tens of seconds. Vision did not affect the amplitude or duration of the post-stimulation effect. The magnitude of post-stimulation CoP displacement was related to the perturbation-induced ML motion of CoP recorded during the stimulation. Over the successive perturbation cycles, the time-course of this motion revealed an adaptation phenomenon. Vision moderately reduced the adaptation rate. The findings support the feasibility of the administration of a simple asymmetric balance perturbation protocol in clinical settings to help patients recover the symmetry of the CoP. This protocol needs to be further validated in older populations and in patients. [ABSTRACT FROM AUTHOR]